scholarly journals Supplementary Light Source Affects Growth, Metabolism, and Physiology ofAdenophora triphylla(Thunb.) A.DC. Seedlings

2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Ya Liu ◽  
Xiuxia Ren ◽  
Byoung Ryong Jeong
Keyword(s):  
Light Source ◽  
Soluble Sugar ◽  
Antioxidant Systems ◽  
Light Sources ◽  
White Led ◽  
Medicinal Species ◽  
Shoot Ratio ◽  
Practical Strategy ◽  
Supplementary Lighting ◽  
Cancer And Inflammation

Adenophora triphylla(Thunb.) A.DC., a well-known herbaceous medicinal species, has been reported to protect against human obesity, cancer, and inflammation. Supplementary lighting is a practical strategy to improve crop quality, especially at a propagation stage. However, there has been no study available on the optimal supplementary light source for the commercial production ofA. triphyllaseedlings. In this study, plug seedlings were cultivated in a greenhouse for four weeks under an average daily light intensity of 490μmol·m−2·s−1PPFD coming from the sun and a supplemental lighting (16 h per day) at 120μmol·m−2·s−1PPFD provided by high pressure sodium (HPS), metal halide (MH), far-red (FR) light, white LED (red: green: blue = 2:4:3, LED-w), or mixed (red: green: blue = 4:1:4) LED (LED-mix). The results showed that LED-mix, with a higher percentage of red and blue light, substantially promoted seedling growth compared to other treatments by increasing stem diameter, biomass, specific leaf weight, and root to shoot ratio. The LED-mix also promoted accumulation of soluble sugar, starch, and chlorophyll in the tissue and increased contents of total phenols and flavonoids. Moreover, stomata density and pore area per leaf area under the LED-mix were remarkably greater than those under other treatments. Furthermore, the Western blot analysis revealed that the expression of photosynthetic protein, D1, was notably enhanced by the LED-mix as compared with other light sources. In addition, the LED-mix alleviated the oxidative damage of seedlings by improving enzymatic and nonenzymatic antioxidant systems. Collectively, these results suggest that the LED-mix was the optimal supplementary light source for the production of highest qualityA. triphyllaseedlings.

scholarly journals Effect of Supplementary Light Source on Quality of Grafted Tomato Seedlings and Expression of Two Photosynthetic Genes

Agronomy ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 207 ◽  
Author(s):  
Hao Wei ◽  
Jiangtao Hu ◽  
Chen Liu ◽  
Mengzhao Wang ◽  
Jin Zhao ◽  
...  
Keyword(s):  
Light Source ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Light Sources ◽  
Seedling Production ◽  
White Leds ◽  
Tomato Seedlings ◽  
Photosynthetic Genes ◽  
Supplementary Lighting

Supplementary lighting is commonly used in high-quality seedling production. In this study, grafted tomato seedlings were grown for 10 days in a glasshouse with 16-h daily supplementary lighting at 100 μmol·m−2·s−1 PPFD (Photosynthetic photon flux density) from either high-pressure sodium (HPS), metal halide (MH), far-red (FR), white LEDs (Light emitting diodes) (W), or mixed LEDs (W1R2B1, where the subscript numbers indicate the ratio of the LED chips) to determine which light sources improve the seedling quality. The control seedlings did not receive any supplementary light. Physiological parameters and the expression of genes related to photosynthesis were analyzed. The results showed that root length, biomass, number of leaves, chlorophyll (SPAD), scion dry weight to height ratio (WHR), and specific leaf weight (SLW) were the greatest for grafted seedlings grown in W1R2B1. The level of root ball formation was the greatest for seedlings grown in W1R2B1, followed by those grown in W, HPS, and MH. Seedlings grown in FR did not fare well, as they were very thin and weak. Moreover, the expression of two photosynthetic genes (PsaA and PsbA) was significantly increased by W1R2B1 and W, which suggests that the plastid or nuclear genes might be regulated. The overall results suggest that W1R2B1 was the most suitable light source to enhance the quality of grafted tomato seedlings. The results of this study could be used as a reference for seedling production in glasshouses, and may provide new insights in the research on lights affecting the development of plants.

A Study on the Effect of Light Sources on the Colour of Objects

2020 ◽  
pp. 47-52
Author(s):  
Fatih Atalar ◽  
Kerim Uzun ◽  
Ahmet Gedikli ◽  
Aysel Ersoy Yilmaz ◽  
Mukden Ugur
Keyword(s):  
Light Source ◽  
Light Sources ◽  
Halogen Lamp ◽  
White Led ◽  
Dominant Wavelength ◽  
Surface Type ◽  
Colour Temperature ◽  
Effect Of Light

Lighting is one of the basic aspects that eases our lives and increases its quality. We use lighting tools in many places such as homes, streets, work places, hospitals, factories, etc. In this study, the effects of the light source and the surface of the object on features like colour temperature, glare, colour (perceived) and dominant wavelength is analysed. Four light sources such as a warm white halogen lamp, warm white LED source and two cool white LED sources were used. In the light measurements, 10 paper surfaces and 8 cloth surfaces were selected as the surface type. Colours of the surfaces were selected among the main colours on the colour locus. Light, reflected from surface was recorded with Konica Minolta CS-200 model. All results were indicated and compared with each other.

scholarly journals Discomfort Glare Caused by White LED Light Sources-Effect of Light Source Position-

2006 ◽  
Vol 90 (11) ◽  
pp. 822-827 ◽  
Author(s):  
Hiroshi Takahashi ◽  
Takashi Irikura ◽  
Masahiro Toda ◽  
Takayoshi Moriyama
Keyword(s):  
Light Source ◽  
Light Sources ◽  
White Led ◽  
Source Position ◽  
Led Light ◽  
Discomfort Glare ◽  
Effect Of Light

scholarly journals Supplementary Light Source Affects the Growth and Development of Codonopsis lanceolata Seedlings

2018 ◽  
Vol 19 (10) ◽  
pp. 3074 ◽  
Author(s):  
Xiuxia Ren ◽  
Ya Liu ◽  
Hai Jeong ◽  
Byoung Jeong
Keyword(s):  
Light Source ◽  
Soluble Sugar ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Root Weight ◽  
Total Biomass ◽  
Codonopsis Lanceolata ◽  
Shoot Weight ◽  
Supplementary Lighting

Codonopsis lanceolata is widely used in traditional medicine and diets. However, there is no optimal protocol for the commercial production of C. lanceolata seedlings. This study was carried out to find the optimum supplementary light source for the production of C. lanceolata seedlings. Seedlings were grown for four weeks in a glasshouse with an average daily light intensity of 490 μmol·m−2·s−1 photosynthetic photon flux density (PPFD) coming from the sun and a 16-h daily supplementary lighting at 120 μmol·m−2·s−1 PPFD from either high-pressure sodium (HPS), metal halide (MH), far-red (FR), white LED (LED-w), or mixed (white: red: blue = 1:2:1) LEDs (LED-mix). The results showed that the greatest total biomass, stem diameter, ratio of shoot weight to shoot length, root biomass, and ratio of root weight to shoot weight were found in seedlings grown under supplementary LED-mix. Meanwhile, the stomatal properties and soluble sugar contents were improved for seedlings in LED-mix. The contents of starch, total phenols, and flavonoids were the greatest for seedlings in LED-w and LED-mix. The expression of photosynthetic proteins and genes in seedlings was also enhanced by LED-mix. Overall, these results suggest that LED-mix is advantageous to the photosynthetic potential and the accumulation of biomass, carbohydrates and secondary metabolites in C. lanceolata.

Organic Light Emitting Diodes - Innovative Light Sources

2019 ◽  
pp. 101-107
Author(s):  
Sergei A. Stakharny
Keyword(s):  
Light Source ◽  
Organic Light Emitting Diodes ◽  
Organic Leds ◽  
Light Sources ◽  
High Quality ◽  
Light Emitting ◽  
Organic Light ◽  
Lighting Systems ◽  
Physical Principles ◽  
Prospects Of Application

This article is a review of the new light source – organic LEDs having prospects of application in general and special lighting systems. The article describes physical principles of operation of organic LEDs, their advantages and principal differences from conventional non-organic LEDs and other light sources. Also the article devoted to contemporary achievements and prospects of development of this field in the spheres of both general and museum lighting as well as other spheres where properties of organic LEDs as high-quality light sources may be extremely useful.

scholarly journals Physiological and Proteomic Responses of Pitaya to PEG-Induced Drought Stress

Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 632
Author(s):  
Aihua Wang ◽  
Chao Ma ◽  
Hongye Ma ◽  
Zhilang Qiu ◽  
Xiaopeng Wen
Keyword(s):  
Drought Stress ◽  
Energy Metabolism ◽  
Metabolic Pathways ◽  
Treatment Time ◽  
Soluble Sugar ◽  
Antioxidant Systems ◽  
Antioxidant Enzyme Activities ◽  
Proteomic Data ◽  
Proteome Profile ◽  
Proteomic Responses

Pitaya (Hylocereus polyrhizus L.) is highly tolerant to drought stress. Elucidating the response mechanism of pitaya to drought will substantially contribute to improving crop drought tolerance. In the present study, the physiological and proteomic responses of the pitaya cultivar ‘Zihonglong’ were compared between control seedlings and seedlings exposed to drought stress (−4.9 MPa) induced by polyethylene glycol for 7 days. Drought stress obviously enhanced osmolyte accumulation, lipid peroxidation, and antioxidant enzyme activities. Proteomic data revealed drought stress activated several pathways in pitaya, including carbohydrate and energy metabolism at two drought stress treatment time-points (6 h and 3 days). Other metabolic pathways, including those related to aspartate, glutamate, glutathione, and secondary metabolites, were induced more at 3 days than at 6 h, whereas photosynthesis and arginine metabolism were induced exclusively at 6 h. Overall, protein expression changes were consistent with the physiological responses, although there were some differences in the timing. The increases in soluble sugar contents mainly resulted from the degradation and transformation of insoluble carbohydrates. Differentially accumulated proteins in amino acid metabolism may be important for the conversion and accumulation of amino acids. GSH and AsA metabolism and secondary metabolism may play important roles in pitaya as enzymatic and nonenzymatic antioxidant systems. The enhanced carbohydrate and energy metabolism may provide the energy necessary for initiating the above metabolic pathways. The current study provided the first proteome profile of this species exposed to drought stress, and may clarify the mechanisms underlying the considerable tolerance of pitaya to drought stress.

scholarly journals Analysis on High-Power Seaport LED Luminaire with Uniform Light Distribution Based on Optimized Lens and Heatsink

2021 ◽  
Vol 11 (9) ◽  
pp. 4035
Author(s):  
Jinsheon Kim ◽  
Jeungmo Kang ◽  
Woojin Jang
Keyword(s):  
Light Source ◽  
High Power ◽  
Heat Dissipation ◽  
Light Emitting Diode ◽  
Light Distribution ◽  
Light Sources ◽  
Led Light ◽  
High Power Led ◽  
Distribution Requirement ◽  
Lighting Application

In the case of light-emitting diode (LED) seaport luminaires, they should be designed in consideration of glare, average illuminance, and overall uniformity. Although it is possible to implement light distribution through auxiliary devices such as reflectors, it means increasing the weight and size of the luminaire, which reduces the feasibility. Considering the special environment of seaport luminaires, which are installed at a height of 30 m or more, it is necessary to reduce the weight of the device, facilitate replacement, and secure a light source with a long life. In this paper, an optimized lens design was investigated to provide uniform light distribution to meet the requirement in the seaport lighting application. Four types of lens were designed and fabricated to verify the uniform light distribution requirement for the seaport lighting application. Using numerical analysis, we optimized the lens that provides the required minimum overall uniformity for the seaport lighting application. A theoretical analysis for the heatsink structure and shape were conducted to reduce the heat from the high-power LED light sources up to 250 W. As a result of these analyses on the heat dissipation characteristics of the high-power LED light source used in the LED seaport luminaire, the heatsink with hexagonal-shape fins shows the best heat dissipation effect. Finally, a prototype LED seaport luminaire with an optimized lens and heat sink was fabricated and tested in a real seaport environment. The light distribution characteristics of this prototype LED seaport luminaire were compared with a commercial high-pressure sodium luminaire and metal halide luminaire.

scholarly journals Towards the Optimum Light Source Spectrum

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Andrew Chalmers ◽  
Snjezana Soltic
Keyword(s):  
Light Source ◽  
Large Scale ◽  
Source Spectrum ◽  
Light Sources ◽  
Luminous Efficacy ◽  
Light Emitting ◽  
Spectral Bands ◽  
Good Energy ◽  
Lighting Systems ◽  
Colour Rendering

This paper is concerned with designing light source spectra for optimum luminous efficacy and colour rendering. We demonstrate that it is possible to design light sources that can provide both good colour rendering and high luminous efficacy by combining the outputs of a number of narrowband spectral constituents. Also, the achievable results depend on the numbers and wavelengths of the different spectral bands utilized in the mixture. Practical realization of these concepts has been demonstrated in this pilot study which combines a number of simulations with tests using real LEDs (light emitting diodes). Such sources are capable of providing highly efficient lighting systems with good energy conservation potential. Further research is underway to investigate the practicalities of our proposals in relation to large-scale light source production.

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